Recurrence \Re*cur"rence\ (r?*k?r"rens), Recurrency \Re*cur"ren*cy\ (-ren*s?), n. [Cf. F. r['e]currence.]

The act of recurring, or state of being recurrent; return; resort; recourse.

I shall insensibly go on from a rare to a frequent recurrence to the dangerous preparations. --I. Taylor.

Source: Webster's Revised Unabridged Dictionary (1913)